[7.3] 66562c8c6 Changelog TLC
Dridi Boukelmoune
dridi.boukelmoune at gmail.com
Mon Nov 13 10:20:08 UTC 2023
commit 66562c8c68cb5467df52c2c2d438ab033be8d1bf
Author: Nils Goroll <nils.goroll at uplex.de>
Date: Wed Oct 18 14:24:56 2023 +0200
Changelog TLC
Conflicts:
doc/changes.rst
diff --git a/doc/changes.rst b/doc/changes.rst
index 3f6397a8d..bcf680fd8 100644
--- a/doc/changes.rst
+++ b/doc/changes.rst
@@ -30,10 +30,101 @@ directory, also available in HTML format at
http://varnish-cache.org/docs/trunk/whats-new/index.html and via
individual releases. These documents are updated as part of the
release process.
+
================================
Varnish Cache 7.3.1 (2023-11-13)
================================
+* Added mitigation options and visibility for HTTP/2 "rapid reset"
+ attacks (CVE-2023-44487_, 3996_, 3997_, 3998_, 3999_).
+
+ Global rate limit controls have been added as parameters, which can
+ be overridden per HTTP/2 session from VCL using the new vmod ``h2``:
+
+ * The ``h2_rapid_reset`` parameter and ``h2.rapid_reset()`` function
+ define a threshold duration for an ``RST_STREAM`` to be classified
+ as "rapid": If an ``RST_STREAM`` frame is parsed sooner than this
+ duration after a ``HEADERS`` frame, it is accounted against the
+ rate limit described below.
+
+ The default is one second.
+
+ * The ``h2_rapid_reset_limit`` parameter and
+ ``h2.rapid_reset_limit()`` function define how many "rapid" resets
+ may be received during the time span defined by the
+ ``h2_rapid_reset_period`` parameter / ``h2.rapid_reset_period()``
+ function before the HTTP/2 connection is forcibly closed with a
+ ``GOAWAY`` and all ongoing VCL client tasks of the connection are
+ aborted.
+
+ The defaults are 100 and 60 seconds, corresponding to an allowance
+ of 100 "rapid" resets per minute.
+
+ * The ``h2.rapid_reset_budget()`` function can be used to query the
+ number of currently allowed "rapid" resets.
+
+ * Sessions closed due to rapid reset rate limiting are reported as
+ ``SessClose RAPID_RESET`` in `vsl(7)` and accounted to
+ ``main.sc_rapid_reset`` in `vsc` as visible through
+ ``varnishstat(1)``.
+
+* A race condition has been fixed in the backend probe code which
+ could trigger a panic with dynamic backends (dyn100_).
+
+* A bug has been fixed in the ESI code which would prevent use of
+ internal status codes >1000 as their modulus 1000 value (3958_).
+
+* Fixed a performance issue in http/2 upload processing (3930_).
+
+* A regression introduced with Varnish Cache 7.3.0 was fixed: On
+ HTTP/2 connections, URLs starting with ``//`` no longer trigger a
+ protocol error (3911_).
+
+* A bug has been fixed where ``unset bereq.body`` had no effect when
+ used with a cached body (3914_).
+
+* Fixed a compatibility issue in the abstract socket support (3908_).
+
+* Improved HPACK header validation.
+
+* HTTP/2 header field validation is now more strict with respect to
+ allowed characters (3952_).
+
+* The ``vcl_req_reset`` feature (controllable through the ``feature``
+ parameter, see `varnishd(1)`) has been added and enabled by default
+ to terminate client side VCL processing early when the client is
+ gone.
+
+ *req_reset* events trigger a VCL failure and are reported to
+ `vsl(7)` as ``Timestamp: Reset`` and accounted to ``main.req_reset``
+ in `vsc` as visible through ``varnishstat(1)``.
+
+ In particular, this feature is used to reduce resource consumption
+ of HTTP/2 "rapid reset" attacks (see below).
+
+ Note, in particular, that *req_reset* events may lead to client
+ tasks for which no VCL is called ever. Presumably, this is thus the
+ first time that valid `vcl(7)` client transactions may not contain
+ any ``VCL_call`` records.
+
+* The ``cli_limit`` parameter default has been increased from 48KB to
+ 64KB.
+
+
+.. _CVE-2023-44487: https://nvd.nist.gov/vuln/detail/CVE-2023-44487
+
+.. _3908: https://github.com/varnishcache/varnish-cache/issues/3908
+.. _3911: https://github.com/varnishcache/varnish-cache/issues/3911
+.. _3914: https://github.com/varnishcache/varnish-cache/issues/3914
+.. _3930: https://github.com/varnishcache/varnish-cache/issues/3930
+.. _3952: https://github.com/varnishcache/varnish-cache/issues/3952
+.. _3958: https://github.com/varnishcache/varnish-cache/issues/3958
+.. _3996: https://github.com/varnishcache/varnish-cache/pull/3996
+.. _3997: https://github.com/varnishcache/varnish-cache/pull/3997
+.. _3998: https://github.com/varnishcache/varnish-cache/pull/3998
+.. _3999: https://github.com/varnishcache/varnish-cache/pull/3999
+
+.. _dyn100: https://github.com/nigoroll/libvmod-dynamic/issues/100
================================
Varnish Cache 7.3.0 (2023-03-15)
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